[Determining guidelines for metals in children's playgrounds in North Rhine-Westphalia]

In 1990, the State of North-Rhine-Westphalia established an ordinance on the quality of playground soil and sand. This ordinance includes guideline values for toxic metals (arsenic, lead, cadmium, chromium) in playground soil not covered by vegetation and quality standards for sand to be applied on playgrounds. Additionally guideline values were set for mercury, nickel and thallium. The guideline values include two categories: guideline value I represents the upper limits (95-percentiles) of the background levels of toxic metals generally found in upper soil layers in the State of North-Rhine-Westphalia. Guideline values II ("action levels") were selected on the basis of toxicological considerations. In cases where concentrations of metals above these guideline values are detected, immediate actions (urgent redevelopment measures) are required. Quality standards for playground sand were established to ensure that only noncontaminated sand is applied for playgrounds.